Warm asphalt has been gaining increasing popularity in the recent years. The asphalt industry has been experimenting with warm and cold asphalt for decades now in order to reduce energy requirements and for environmental benefits. Apart from the obvious advantages like reduced fuel consumption and reduced emissions in the plant, there are several other advantages of using warm asphalt like longer paving ‘seasons’, longer hauling distances, reduced wear and tear of the plants, reduced ageing of binders, reduced oxidative hardening of binders and thus reduce cracking in the pavements, ability of opening the site to traffic sooner, etc. Until now, most of the cold products were inferior to hot mix asphalt. However, with the availability of several proprietary chemicals and processes to produce warm asphalt, it is now possible to produce warm asphalt without affecting the properties of the mix.

While the energy savings and the air quality improvements by using warm asphalt are appealing, the performance of warm asphalt in the United States is not well known. Some of the immediate concerns with warm asphalts are properties of the warm asphalt like indirect tensile strengths, rutting, moisture susceptibility, etc. with respect to hot mix asphalt, increased curing times, ageing behavior of warm asphalt, compatibility with current construction practices and equipments, compatibility with rubberized asphalt binder, compatibility with recycled asphalt pavements, etc. While some studies have been conducted to address some of the issues, there is still a lot not known about warm asphalt.

The main objective of the research project is to investigate the performance of warm mix asphalt as compared to hot mix asphalt. The specific objectives of the research project include the following:

• To study the performance of warm mix asphalt with respect to hot mix asphalt in terms of indirect tensile strength, rutting and resilient modulus.
• To study the rheological properties of the warm asphalt binder.
• To study the compatibility of warm asphalt technologies with rubber modified asphalt binder.
• To study the compatibility of the warm asphalt technologies with recycled asphalt pavement materials.
• To develop a systematic standard specification for the use of warm asphalt.